1. Field of the Invention
The invention relates to transient voltage; in particular, to a transient voltage suppressor (TVS).
2. Description of the Prior Art
In general, electrostatic discharge is one of the important factors affecting the yield and reliability of electronic products. Especially, because there are a lot of hot-swap interfaces in recent electronic products and the changes in consumer behavior, the risk of electrostatic discharge causing damage to electronic products becomes higher. Therefore, many manufacturers have raised the electrostatic discharge test specifications to the highest level. Among the many electrostatic protector products, the transient voltage suppressor array (TVS array) has the advantages of fast conduction speed and low clamping voltage, and has become the best choice for meeting the highest level of electrostatic discharge test specifications.
Please refer to FIG. 1. FIG. 1 illustrates a diagram showing current-voltage characteristic curves of a conventional transient voltage suppressor. As shown in FIG. 1, when the forward voltage +V is small, the transient voltage suppressor exhibits a high resistance characteristic and is in an OFF state; when the forward voltage +V reaches a breakdown voltage VBR, the transient voltage suppressor will be turned on and in an ON state, and its resistance will become smaller. This phenomenon of pulling the voltage from the OFF state to the ON state is called “Snap back”, and the magnitude of the turn-on voltage VON is usually determined by the amount of current received by the gate.
However, the structure of the conventional transient voltage suppressor is complicated, and the gate structure is required to control the turn-on voltage VON. In addition, when an electrostatic discharge event occurs, the current in the conventional transient voltage suppressor is concentrated in the same current path causing the overall resistance of the transient voltage suppressor to be difficult to reduce.